The present invention relates in general to opposed piston, direct injected, two strokes per cycle (two stroke), Internal Combustion (IC), opposed piston engines, and more particularly to new, improved technology for design and operation of these types of engines that provides, among other things, higher efficiency, more complete combustion, lower emissions, higher power per unit of displacement, and greater mechanical simplicity than prior art IC engines.
It is well known by those skilled in the art that in a direct injected, state of the art diesel combustion chamber the distance between the tip of the injection nozzle in the direction of the fuel spray and the end of the combustion chamber (burn length) is much less than desirable. When unburned fuel strikes a metal surface it fails to burn completely causing undesirable carbon emissions including PM10. But the volume of the combustion chamber must be kept very small to achieve the compression ratio necessary to ignite the fuel. So far the use of a single injector tip with multiple holes spraying fuel out into a partial toroidal shaped combustion chamber has proven to be the best design technology available for the present state of the art diesel engine even though some of the fuel remains unburned.
There is another problem with this shaped combustion chamber. It has significantly more surface area than that of more compact chambers of the same volume. The larger surface area causes added heat loss at the critical time of combustion which decreases the power and efficiency of the engine.
Because of the extreme pressure on the top of the piston at the time of combustion in the present state of the art diesel engine the crank shaft must be fitted with high friction, oil pressurized journal bearings and can not be successfully fitted with low friction roller bearings. And because of the oscillating motion of the connecting rods the pistons are forced back and forth against the cylinder walls causing even more friction and wear. These added frictional forces also decrease the power and efficiency of the engine. Accordingly, the need exists for a direct injected, IC engine that overcomes the afore described inefficiencies.
Known two-stroke engines required some form of supercharging to fill the cylinders. The power required to drive the supercharger reduces the efficiency of the known two-stroke engines.
Known Scotch yoke engines created significant wear on the Scotch yokes when combustion takes place. Known Scotch yokes design, for example, U.S. Pat. No. 1,687,425, include features to deal with this wear, but not to reduce or prevent the wear.